New opera update looks ugly visually and there needs to be an option to change it

I hate the new update, I find the new border and highlight on the current tab tacky and distracting but I especially found the changes to the sidebar an absolute travesty, making the icons full squares is whatever but making them smaller for the sake of the new border is just gross and goes against the purpose of the sidebar which was to increase convenience.

I see how the visuals can appeal to some audience but personally I don't like it at all, there should be an option to revert to the old GUI